PFD and resetting phone

I will shortly be getting a new phone (930) and want to give my 920 which is running PFD to my girlfriend. I have 2 questions in regards to this.
1. to reset my phone and clear it of ALL data settings etc etc is it enough just to go into 'about phone' in settings and hit reset?

so, if PFD has that device (920) registered with my Microsoft account, will that then cause problems for me having a new device (and also if I want to enrol that new device in PFD also) being registered with the same Microsoft account.
Will it cause problems for my girlfriend if she wants to set up the 920 with her Microsoft account?

so, if PFD has that device (920) registered with my Microsoft account, will that then cause problems for me having a new device (and also if I want to enrol that new device in PFD also) being registered with the same Microsoft account.
Will it cause problems for my girlfriend if she wants to set up the 920 with her Microsoft account?

[1] You can install PFD with your MS account(One which is currently used by your 920) again on new device. It wont pose any problem.

[2] She can easily set up your device(920) with her MS account, it wont be an issue. Just in case, if she would like to install future PFD updates, she needs to sign in with her ID using Preview for developers app.